1. Field of the Invention
This invention relates to a lock arm for locking the fitting connection between male and female connectors, and more particularly to a lock arm deformation prevention construction for preventing plastic deformation of the lock arm so as to prevent the incomplete locking of the fitting connection.
The present application is based on Japanese Patent Application No. Hei. 9-183844, which is incorporated herein by reference.
2. Description of the Related Art
FIG. 6 shows male and female connectors, in which a conventional lock arm is formed on the male connector. Female terminals 22 are retained in a housing 21 of the male connector 20 respectively by housing lances 33, and male terminals 25 are retained in a housing 24 of the female connector 23 respectively by housing lances 34. The male connector 20 is inserted into a tubular portion 32 formed at a front end of the female connector housing 24, so that the male terminals 25 are fitted into and electrically connected to the female terminals 22, respectively.
A lock arm 27, having an engagement projection 28, is formed on the male connector 20, and a flexing space 26 is formed on the lower side of the lock arm 27. A slit 30 for receiving the engagement projection 28 is formed in the tubular portion 32 of the female connector 23.
For fitting the male connector 20 into the female connector 23, the male connector 20 is inserted into the tubular portion 32 of the female connector 23 while pressing down a press portion 31 provided at a distal end of the lock arm 27, and when the engagement projection 28 is brought into a position where this projection 28 can fit into the slit 30, the application of a pressing force to the press portion 31 is stopped. As a result, the engagement projection 28 is fitted into the slit 30, and engages an engagement portion 29 formed at a front end of the slit 30, so that the two connectors are held in a mutually-fitted condition, and also each pair of male and female connection terminals are kept in an electrically-connected condition.
When it is desired to intentionally disconnect or disengage the male and female connectors, fitted together, from each other, the press portion 31 is pressed down, thereby disengaging the engagement projection 28 from the engagement portion 29, and in this condition the two connectors are moved away from each other.
However, if an external force F continues to act on the press portion 31 of the male connector 20, having the above lock arm, when the male connector 20 is in its independent condition, that is, not fitted in the female connector 23, and can be subjected to an external force from other parts, for example, during transport, this leads to the possibility that the lock arm 27 is plastically deformed.
If the lock arm 27 is plastically deformed, the engagement of the engagement projection 28 with the engagement portion 29 is incomplete as shown in FIG. 6 when the male connector 20 is fitted in the female connector 23, and even when the press portion 31 is not pressed down, the two connectors can be easily disengaged from each other upon application of an external force tending to move the two connectors away from each other. If such connectors are mounted, for example, on an automobile or the like, the mutually-engaged condition of the two connectors is canceled by vibrations developing during the running, so that each female terminal 22 is disconnected from the associated male terminal 25, thus breaking the electric circuit, which may cause a grave accident.